JPH0913295A - Liquid agent for improving surface quality of paper - Google Patents

Abstract

PURPOSE: To improve the surface strength, internal bond strength and sizing effect of paper in balanced state and impart the paper with excellent stability. CONSTITUTION: The objective liquid agent contains a mixed aqueous solution of (A) at least one kind of resin selected from styrene-acrylic acid resin, styrene- acrylic acid-acrylic acid ester resin, styrene-maleic acid resin, styrene-maleic acid-maleic acid half-ester resin, (di)isobutylene-maleic acid resin and (di) isobutylene-maleic acid-maleic acid half-ester resin and (B) an acrylamide resin produced by reacting (a) an acrylamide compound with (b) an anionic vinyl monomer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface paper quality improving liquid agent which improves the surface strength, internal strength and size effect of paper in a well-balanced manner and is excellent in product stability.

[0002]

2. Description of the Related Art In recent years, the development of printing technology has been remarkable, and with the increase in printing speed and quality, it has become more and more demanding for printing paper to improve its printability such as surface strength, internal strength and size. It has come to be demanded. In order to meet these requirements, papermaking chemicals have been added (internally added) to an aqueous pulp slurry or coated (externally added) on the surface of paper. Of these, the internal additive has an insufficient chemical yield, while the external additive has a chemical yield of almost 100.
%, Which is known to be more advantageous because it acts directly on the surface of the paper. Conventionally, a mixture of alkenyl succinate and polyacrylamide type substances (Japanese Patent Publication No. 60
No. 10160) is known.

[0003]

However, the conventional surface paper quality improvers have not been sufficiently satisfactory in response to the recent demand for a high degree of surface paper quality improvement. However, it was insufficient to improve the size property in a well-balanced manner. For example, when the above-mentioned conventional surface paper quality improver is applied to a non-sized paper by a gate roll coater, a size press, etc., the surface strength and internal strength are improved, but the sizing property is not sufficiently improved. . Also,
When the same is applied to strong size paper, the size effect is not improved but rather deteriorated, which is regarded as a problem.

Therefore, if the mixing ratio of the hydrophobic component (alkenyl succinate) of the above-mentioned surface paper quality improver of the prior art is increased in order to improve the size effect, the size property is improved, while the surface strength is improved. However, the internal strength is significantly reduced, which is not preferable. Also, without changing the mixing ratio,
The method of increasing the hydrophobicity of the hydrophobic component itself (alkenyl succinate) to enhance the size effect is not preferable because it reduces the compatibility with the polyacrylamide-based substance used in combination. Therefore, it has been strongly desired to develop a surface paper quality improving agent that improves the surface strength and the internal strength as well as the size property in a well-balanced manner. The present invention provides a surface paper quality improving liquid agent for solving the above problems.

[0005]

Means for Solving the Problems The inventors of the present invention have conducted diligent research to meet the demand, and as a result, styrene-acrylic acid resin, styrene-acrylic acid-acrylic acid ester resin, styrene-maleic acid resin, styrene. -Maleic acid-Maleic acid half ester resin, (di) isobutylene-
1 to 50 parts by weight of at least one resin [A] selected from the group consisting of maleic acid resin and (di) isobutylene-maleic acid-maleic acid half-ester resin, 100 parts by weight of acrylamides (a), and anionic Surface paper quality improvement containing a mixed aqueous solution of an acrylamide resin [B] obtained by reacting 0.5 to 50 parts by weight of a vinyl monomer (b) and optionally 0.005 to 10 parts by weight of a crosslinking agent (c). By using a liquid agent, it was found that the size effect can be improved in a well-balanced manner as well as the surface strength and the internal strength, and the present invention has been completed.

That is, the present invention relates to a styrene-acrylic acid resin, a styrene-acrylic acid-acrylic acid ester resin, a styrene-maleic acid resin, a styrene-maleic acid-maleic acid half-ester resin, a (di) isobutylene-maleic acid resin, (Di) 1 to 50 parts by weight of at least one resin [A] selected from the group consisting of isobutylene-maleic acid-maleic acid half ester resin, 100 parts by weight of acrylamides (a), and anionic vinyl monomer (b). ) A surface paper quality improving liquid agent containing a mixed aqueous solution of an acrylamide resin [B] obtained by reacting 0.5 to 50 parts by weight,

Alternatively, styrene-acrylic acid resin, styrene-acrylic acid-acrylic acid ester resin, styrene-maleic acid resin, styrene-maleic acid-maleic acid half ester resin, (di) isobutylene-maleic acid resin, (di) isobutylene 1-50 parts by weight of at least one resin [A] selected from the group consisting of maleic acid-maleic acid half-ester resin, and acrylamides (a) 1
00 parts by weight and 0.5 of the anionic vinyl monomer (b)
A surface paper quality improving liquid agent containing a mixed aqueous solution of acrylamide resin [B] obtained by reacting ˜50 parts by weight with 0.005 to 10 parts by weight of a crosslinking agent (c) is provided.

The resin [A] is preferably a styrene-acrylic acid resin, and the acrylamides (a) are preferably acrylamide or methacrylamide. Further, the anionic vinyl monomer (b) is an unsaturated monocarboxylic acid, an unsaturated dicarboxylic acid,
It is preferably at least one selected from the group consisting of unsaturated tricarboxylic acid, unsaturated tetracarboxylic acid, unsaturated sulfonic acid, unsaturated phosphonic acid, and salts thereof.

Next, the present invention will be described in detail. The resin [A] used in the present invention is styrene-acrylic acid resin, styrene-acrylic acid-acrylic acid ester resin, styrene-maleic acid resin, styrene-maleic acid-maleic acid half ester resin, (di) isobutylene-malein. The acid resin and the (di) isobutylene-maleic acid-maleic acid half ester resin may be polymerized by any method such as bulk polymerization, solution polymerization and emulsion polymerization, but a bulk polymerization product is particularly preferable. When a powdered resin is used, it needs to be saponified to form an aqueous solution before or during the polymerization.

The alkali used for saponification is one or two selected from sodium hydroxide, potassium hydroxide, ammonia, sodium silicate, sodium aluminate, monoethanolamine, triethanolamine and the like.
More than one organic or inorganic alkali can be used. Also, styrene and acrylic acid, styrene and acrylic acid and acrylic ester, styrene and maleic acid, styrene and maleic acid and maleic acid half ester, (di) isobutylene and maleic acid, (di) isobutylene and maleic acid and maleic acid half ester. The composition ratio and molecular weight of the ester are not particularly limited as long as they do not impair the compatibility with the acrylamide resin [B].

As the resin [A], GSA2302 (styrene-acrylic acid resin: manufactured by Gifu Shellac), GSA
2303 (styrene-acrylic acid-acrylic acid ester resin: manufactured by Gifu Shellac), SMA3000 (styrene-maleic acid resin: manufactured by Elf Atchem), SMA2
000 (styrene-maleic acid resin: manufactured by Elf Atchem), isoban 10 (isobutylene-maleic acid resin: manufactured by Kuraray Co., Ltd.) and the like. Particularly, styrene-acrylic acid resin is preferable.

Next, the acrylamide resin [B] used in the present invention will be described. As the acrylamides of the component (a) used in the acrylamide resin [B], acrylamide and methacrylamide are preferable, and N-methyl (meth) acrylamide, N-ethyl (meth) acrylamide, N, N-dimethyl ( Any one or more of N-substituted acrylamides such as (meth) acrylamide, N-isopropyl (meth) acrylamide, and Nt-octyl (meth) acrylamide can be used in combination with acrylamide and methacrylamide.

Unsaturated monocarboxylic acid, unsaturated dicarboxylic acid, unsaturated tricarboxylic acid, unsaturated tetracarboxylic acid, unsaturated sulfonic acid, which is the anionic vinyl monomer of the component (b) used in the acrylamide resin [B], The unsaturated phosphonic acid and salts thereof are exemplified below.

Examples of the unsaturated monocarboxylic acid and salts thereof include acrylic acid, methacrylic acid and their alkali metal salts such as sodium and potassium salts, ammonium salts and the like.

Examples of unsaturated dicarboxylic acids and salts thereof include maleic acid, fumaric acid, itaconic acid, citraconic acid and their alkali metal salts such as sodium and potassium salts, or ammonium salts.

Examples of unsaturated tricarboxylic acids and salts thereof include aconitic acid, 3-butene-1,2,3-tricarboxylic acid, 4-pentene-1,2,4-tricarboxylic acid and their sodium and potassium salts. Examples thereof include alkali metal salts and ammonium salts.

The unsaturated tetracarboxylic acid and salts thereof include 1-pentene-1,1,4,4-tetracarboxylic acid, 4-pentene-1,2,3,4-tetracarboxylic acid and 3-hexene. Examples thereof include -1,1,6,6-tetracarboxylic acid and their alkali metal salts such as sodium and potassium salts or ammonium salts.

Examples of the unsaturated sulfonic acid include vinyl sulfonic acid, styrene sulfonic acid, allyl sulfonic acid, 2-acrylamido-2-methylpropane sulfonic acid and their alkali metal salts such as sodium and potassium salts or ammonium salts. To be

Examples of the unsaturated phosphonic acid include vinylphosphonic acid, α-phenylvinylphosphonic acid and their alkali metal salts such as sodium and potassium salts or ammonium salts.

Of the above anionic vinyl monomers, itaconic acid, acrylic acid and salts thereof are preferable, and itaconic acid and salts thereof are particularly preferable. As a method of introducing the anionic group, a method of introducing the anionic group by hydrolyzing the acrylamide resin [B] with an acid or an alkali can be used in addition to the method of using the anionic vinyl monomer.

In addition to the above components (a) and (b), the compatibility of the copolymerizable cationic vinyl monomers such as dimethylaminopropyl (meth) acrylamide and its quaternary products, or the obtained acrylamide resin [B]. Also, nonionic vinyl monomers in an amount that does not impair the water solubility can be used.

Examples of the cationic vinyl monomer include dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) acrylate, diethylaminopropyl (meth) acrylate, dimethylaminopropyl (meth) acrylamide or diethylamino. Vinyl monomers having tertiary amino groups such as propyl (meth) acrylamide, alkyldiallylamine, dialkylallylamine, diallylamine and allylamine, secondary amino groups and primary amino groups, or salts thereof, sulfuric acid, formic acid,
Salts of inorganic or organic acids such as acetic acid,

Alternatively, the vinyl monomer containing a tertiary amino group and an alkyl halide such as methyl chloride or methyl bromide, an arylalkyl halide such as benzyl chloride or benzyl bromide, dimethylsulfate, diethylsulfate, epichlorohydrin or 3-chloro-2. A vinyl monomer containing a quaternary ammonium salt obtained by reaction with a quaternizing agent such as hydroxypropyltrimethylammonium chloride or glycidyltrialkylammonium chloride, eg 2-hydroxy-N, N,
N, N ', N'-pentamethyl-N'-[3-{(1-
Oxo-2-propenyl) amino} propyl] -1,3
-Propanediaminium dichloride and the like are exemplified, and these can be used alone or in combination of two or more.

Examples of the nonionic vinyl monomer include acrylonitrile, methacrylonitrile, styrene, methyl vinyl ether, alkyl ester of (meth) acrylic acid, 2-hydroxy ester, glycidyl ester and the like, and one of these may be used alone or two of them may be used. The above can be used in combination.

The cross-linking agent (c) used in the present invention includes
Di (meth) acrylates such as ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, glycerin di (meth) acrylate, trimethylolpropane -Ethylene oxide adduct triacrylate, methylenebis (meth) acrylamide, ethylenebis (meth) acrylamide, hexamethylenebis (meth) acrylamide, N, N'-bisacrylamidoacetic acid, N, N'-bisacrylamidoacetate methyl, N, N
-Bis (meth) acrylamides such as benzylidene bisacrylamide,

Divinyl esters such as divinyl adipate and divinyl sebacate, epoxy acrylates, urethane acrylates, allyl (meth) acrylate,
Bifunctional vinyl monomers such as diallyl phthalate, diallyl malate, diallyl succinate, diallyl acrylamide, divinyl benzene, diisopropyl benzene, N, N-diallyl methacrylamide, diallyl dimethyl ammonium, diallyl chlorendate and glycidyl (meth) acrylate, Trifunctional vinyl monomers such as 1,3,5-triacryloylhexahydro-S-triazine, triallyl isocyanurate, N, N-diallyl acrylamide, triallylamine and triallyl trimellitate,

Tetramethylolmethane tetraacrylate, tetraallyl pyromellitate, N, N, N ', N'
-Tetrafunctional vinyl monomers such as tetraallyl-1,4-diaminobutane, tetraallylamine salt and tetraallyloxyethane, tetramethylolmethane-tri-β-aziridinylpropionate, trimethylolpropane-
Tri-β-aziridinyl propionate, 4,4′-
Water-soluble aziridinyl compounds such as bis (ethyleneiminecarbonylamino) diphenylmethane, (poly) ethylene glycol diglycidyl ether, (poly) propylene glycol diglycidyl ether, (poly) glycerin diglycidyl ether, (poly) glycerin triglycidyl ether, etc. Water-soluble polyfunctional epoxy compound,

And 3- (meth) acryloxymethyltrimethoxysilane, 3- (meth) acryloxypropyldimethoxymethylsilane, 3- (meth) acryloxypropyltrimethoxysilane, 3- (meth) acryloxypropylmethyldi Chlorosilane, 3- (meth) acryloxyoctadecyltriacetoxysilane, 3- (meth) acryloxy-2,5-dimethylhexyldiacetoxymethylsilane, 3- (meth) acrylamidopropyltrimethoxysilane, 2- (meth) acrylamidoethyl. Trimethoxysilane, 1- (meth) acrylamidemethyltrimethoxysilane, 2- (meth) acrylamide-2
-Methylpropyltrimethoxysilane, 2- (meth) acrylamido-2-methylethyltrimethoxysilane,

2- (meth) acrylamidoisopropyltrimethoxysilane, 3- (meth) acrylamidopropyltriethoxysilane, N- (2- (meth) acrylamidoethyl) aminopropyltrimethoxysilane,
(3- (meth) acrylamidopropyl) oxypropyltrimethoxysilane, 3- (N-methyl (meth) acrylamide) propyltrimethoxysilane, 3-((meth) acrylamide-methoxy) -3-hydroxypropyltrimethoxysilane, 3-((meth) acrylamide-methoxy) propyltrimethoxysilane, 3- (vinylbenzylaminopropyl) trimethoxysilane,

Dimethyl-3- (meth) acrylamide-
Propyl-3- (trimethoxysilyl) -propylammonium chloride, dimethyl-2- (meth) acrylamido-2-methylpropyl-3- (trimethoxysilyl) -propylammonium chloride, 3- (meth)
Acrylamidopropylmethyldimethoxysilane, 3-
(Meth) acrylamidopropyldimethylmethoxysilane, 3- (meth) acrylamidopropylisobutyldimethoxysilane, 2- (meth) acrylamidopropylisobutyldimethoxysilane, 2- (meth) acrylamido-2-methylpropylmonochlorodimethoxysilane, 2- (meta ) Acrylamido-2-methylpropylhydrogendimethoxysilane,

3- (meth) acrylamidopropylbenzyldiethoxysilane, 3- (meth) acrylamidopropyltriacetoxysilane, 2- (meth) acrylamidoethyltriacetoxysilane, 4- (meth) acrylamidobutyltriacetoxysilane, 2- (Meth) acrylamido-2-methylpropyltriacetoxysilane, N- (2- (meth) acrylamidoethyl) aminopropyltriacetoxysilane, 2- (N-ethyl (meth) acrylamide) ethyltriacetoxysilane, 3
-(Meth) acrylamidopropyloctyldiacetoxysilane, 1- (meth) acrylamidomethylphenyldiacetoxysilane,

3- (meth) acrylamidopropyltripropionyloxysilane, 3- (meth) acrylamidopropyltri (N-methylaminoethoxy) silane, vinyltrichlorosilane, vinylmethyldichlorosilane,
Divinyldichlorosilane, vinylphenyldichlorosilane, vinyldimethylchlorosilane, vinylmethylphenylchlorosilane, vinyldiphenylchlorosilane, vinyltrimethoxysilane, vinylmethyldimethoxysilane, vinylisobutyldimethoxysilane, vinyldimethylmethoxysilane, vinyltriethoxysilane, 3-vinyl Benzylaminopropyltriethoxysilane, vinylmethyldiethoxysilane,

Divinyldiethoxysilane, vinyldimethylethoxysilane, vinyldiphenylethoxysilane,
Vinyltriisopropoxysilane, vinyltributoxysilane, vinyldimethylisobutoxysilane, vinyltriphenoxysilane, vinyldimethyl (3-aminophenoxy) silane, vinyldimethyl (4-aminophenoxy) silane, vinyldimethyl (3-methyl-4) -Chlorophenoxy) silane, vinyldimethyl (2-methyl-4)
Examples thereof include silicon compounds such as -chlorophenoxy) silane, vinyltriacetoxysilane, vinylmethyldiacetoxysilane, and vinyldimethylacetoxysilane.

The amount of the resin [A] used in the present invention is 1 to 50 parts by weight based on 100 parts by weight of the acrylamide (a) used in the acrylamide resin [B].
-30 parts by weight is preferred.

The reaction of the acrylamide resin [B] of the present invention is carried out by using a suitable polymerization initiator at a temperature of 40 to 100 ° C. for 0.5 to 10 hours. The weight ratio of each of the components (b) and (c) to 100 parts by weight of the acrylamides (a) is as follows. The anionic vinyl monomer (b) is 0.5 to 50 parts by weight, preferably 2 to 20 parts by weight, and the crosslinking agent (c) is 0.005 to 10 parts by weight, preferably 0.01 to 2 parts by weight. is there.

When the weight ratio of the resin [A], the anionic vinyl monomer (b) and the cross-linking agent (c) is out of this range, the surface strength, internal strength and size effect cannot be improved in a good balance, which is preferable. Absent. In particular, resin [A]
When it exceeds 50 parts by weight, the stability as an aqueous solution mixed with the resulting acrylamide resin [B] is poor, which is not preferable.

The polymerization initiator used in the present invention is not particularly limited, and known and commonly used ones can be used. For example, a radical polymerization initiator such as sodium persulfate, potassium persulfate, ammonium persulfate, hydrogen peroxide, and a ceric salt is added in an amount of 0.01 with respect to the total weight of the acrylamides (a) and the anionic vinyl monomer (b). ~
Use 5% by weight. Further, redox polymerization can be carried out by using a reducing agent such as dimethylamine, sodium hydrogen sulfite and sodium formaldehyde sulfoxylate in combination.

If necessary, a known and commonly used chain transfer agent may be used. Examples thereof include allyl compounds such as allyl alcohol and allylamine, mercaptoethanol, thioglycolic acid or its alkali metal salts or ammonium salts, isopropyl alcohol, and sodium hypophosphite.

The surface paper quality improving liquid of the present invention or the coating liquid containing the same is added to an anti-slip agent, a release agent, a rust preventive, a preservative, an antifoaming agent, a viscosity modifier, a dye, a surface sizing agent, a water repellent. You may add additives, such as. Further, the combination with natural or synthetic polymers such as starches, polyvinyl alcohol and carboxymethyl cellulose, and the combination with other surface paper quality improvers are not limited. In addition, the solid content concentration of the coating liquid is usually 0.1 to 15%.

The surface coating solution containing the surface paper quality improving liquid agent of the present invention is applied to paper or paperboard by a method such as size press, film press, gate roll coater, blade coater or calender. It is preferable. Also, bar coater, knife coater,
It can also be coated with an air knife coater or the like.

The coating liquid containing the surface paper quality improving liquid agent of the present invention can be applied to acidic paper or neutral paper. Types of acid paper or neutral paper include coated base paper, newsprint, liner, coated ball, printing writing paper, foam paper, PPC paper, inkjet paper,
Examples include various base papers such as thermal transfer paper and thermal paper. The sizing degree of the base paper is also arbitrary, but when applying using a size press or the like, it is desirable to use an internal sizing agent for the purpose of adjusting the liquid absorption of the base paper.

[0042]

The present invention will be described in detail below with reference to examples and comparative examples, but the present invention is not limited to the following examples. Unless otherwise specified, parts and% mean parts by weight and% by weight.

Synthesis Example 1 (Synthesis of Acrylamide Resin [B]) 251 parts of water, 50% in a 1 liter four-necked flask equipped with a stirrer, thermometer, reflux condenser and nitrogen gas inlet tube.
200 parts of an acrylamide aqueous solution, 4 parts of itaconic acid, and 40 parts of isopropyl alcohol were charged, and the temperature was raised to 60 ° C. Then, 3.3 parts of a 5% ammonium persulfate aqueous solution was added under the introduction of nitrogen gas, the temperature was raised to 80 ° C., and the reaction was carried out for 2 hours. 22 parts of water was added to the obtained reaction product to obtain a water-soluble resin having a solid content of 20.3% and a viscosity of 4100 cps.
This is designated as resin m.

Synthetic Examples 2 to 6 Resins n to r were obtained in the same manner as in Synthetic Example 1 except that the type and amount of the anionic vinyl monomer were changed as shown in Table 1.

Example 1 104 parts of resin m and 10 parts of 20% aqueous ammonia solution of GSA2302 (styrene-acrylic acid resin) were mixed.
The obtained mixed aqueous solution is referred to as Resin A.

Examples 2 to 6 and Comparative Examples 1 to 4 Resin [A] and acrylamide resin [B] shown in Table 2 were mixed in the same manner as in Example 1 to prepare resins BF and resins x to z (comparative). I got) Further, Comparative Example 1 is a case where only the resin m is used.

Example 7 The above resins A to F, resins m and x to z (comparative example) were diluted with water to prepare a coating liquid having a solid content concentration of 3%. This coating solution was applied to uncoated newsprint paper (basis weight: 43.5 [g / m ² ]). One side was coated using a 3 bar coater and dried with a drum dryer (80 ° C., 50 seconds). After drying 2
The humidity was controlled for 24 hours in a constant temperature and humidity room at 0 ° C. and a relative humidity of 65% RH, and then various evaluation tests were performed. Table 3 shows the results. An example in which only water is applied is shown in Table 3. Further, Table 2 shows the evaluation results of the storage stability of the resins A to F, m and x to z.

The evaluation test was carried out by the following measuring method. Surface strength: Dry pick; RI printing tester, nip width 10 mm Ink: FINE INK. (Manufactured by Dainippon Ink and Chemicals, Inc.) V. = 24 In all cases, the peeled state of the paper after printing was observed with the naked eye, and 5 was evaluated as excellent and 1 was inferior, and a 5-level evaluation was performed. Internal strength: Scott bond (kgf · cm); Internal bond tester (manufactured by Kumagai Riki Kogyo Co., Ltd.) is used for adhesive strength 5 kg.
/ Cm ² , 30 seconds was measured. Size: Drop test (seconds); TAPPI 33 (water 5μ
It carried out according to l). Storage stability: The product was allowed to stand at 40 ° C., and product separation, white turbidity, generation of aggregates, etc. were observed. ○: Excellent △: Good ×: Poor

As is clear from the test results in Table 3, all the resins of the examples were excellent in surface strength, internal strength, and size effect in good balance and excellent in stability. On the other hand, the resin of Comparative Example did not improve the surface strength, the internal strength and the size effect in a well-balanced manner (for example, the resin m of Comparative Example 1 had the same excellent surface strength and internal strength as the resin of the Example). , But the size effect was clearly inferior).

[0050]

[Table 1]

[0051]

[Table 2]

[0052]

[Table 3]

[0053]

The surface paper quality improving liquid agent of the present invention improves the surface strength, internal strength and size effect of paper in a well-balanced manner.
It also exhibits excellent stability.

Claims (5)

[Claims] 1. Styrene-acrylic acid resin, styrene-
Acrylic acid-acrylic acid ester resin, styrene-maleic acid resin, styrene-maleic acid-maleic acid half ester resin, (di) isobutylene-maleic acid resin,
1 to 50 parts by weight of at least one resin [A] selected from the group consisting of (di) isobutylene-maleic acid-maleic acid half-ester resin, and acrylamides (a) 10
0 parts by weight and an anionic vinyl monomer (b) 0.5 to
A surface paper quality improving liquid agent comprising a mixed aqueous solution of an acrylamide resin [B] obtained by reacting 50 parts by weight. 2. Styrene-acrylic acid resin, styrene-
Acrylic acid-acrylic acid ester resin, styrene-maleic acid resin, styrene-maleic acid-maleic acid half ester resin, (di) isobutylene-maleic acid resin,
1 to 50 parts by weight of at least one resin [A] selected from the group consisting of (di) isobutylene-maleic acid-maleic acid half-ester resin, and acrylamides (a) 10
0 parts by weight and an anionic vinyl monomer (b) 0.5 to
A surface paper quality improving liquid agent comprising 50 parts by weight and a mixed aqueous solution of an acrylamide resin [B] obtained by reacting 0.005 to 10 parts by weight of a crosslinking agent (c). 3. The anionic vinyl monomer (b) is composed of unsaturated monocarboxylic acid, unsaturated dicarboxylic acid, unsaturated tricarboxylic acid, unsaturated tetracarboxylic acid, unsaturated sulfonic acid, unsaturated phosphonic acid and salts thereof. The surface paper quality improving liquid agent according to claim 1 or 2, which is at least one selected from the group. 4. The surface paper quality improving liquid agent according to claim 1, wherein the resin [A] is a styrene-acrylic acid resin. 5. The surface paper quality improving liquid agent according to claim 1, wherein the acrylamides (a) are acrylamide and methacrylamide.